System for preparing hydrogen-rich synthesis gas through biomass grading gasification

Abstract

The invention discloses a system for preparing hydrogen-rich synthesis gas by biomass graded gasification. Biomass is subjected to pretreatment modification and directional pyrolysis to obtain volatile components and high-yield pyrolysis coke, the pyrolysis coke is gasified by water vapor to prepare clean hydrogen-rich synthesis gas, and the volatile components are completely combusted to obtain high-temperature flue gas; and the high-temperature flue gas supplies heat to gasification and pyrolysis processes in sequence through indirect heat exchange, and heats water to form water vapor. According to the invention, the pyrolysis and gasification processes are graded, and only high-yield pyrolysis coke gasification is utilized to avoid volatile component gasification so as to prepare the hydrogen-rich synthesis gas, so that the formation of tar is inhibited from the source; and the pyrolysis coke yield and the gasification reaction activity are improved through pretreatment modification and pyrolysis process regulation and control, so that the carbon atom utilization economy and selectivity of the hydrogen-rich synthesis gas prepared from the biomass are improved; the volatile components are completely combusted for heat supply so as to realize process heat self-maintenance; and the prepared gas is high in grade and cleaner, effectively breaks through the bottleneck faced by the current biomass pyrolysis gasification technology, and has good technical economy.

Description

technical field [0001] The invention belongs to the technical field of biomass energy, and in particular relates to a system for producing hydrogen-rich synthesis gas through staged gasification of biomass. Background technique [0002] Biomass is an important clean and renewable energy with CO 2 The advantages of near-zero emissions are expected to play a more important role under the 2050 carbon neutral vision. However, my country's current various biomass energy conversion and utilization technologies are still immature. To a certain extent, there are problems such as low utilization efficiency, low product quality, and low technical and economic efficiency. The profitability of enterprises is weak and unsustainable, which greatly limits Its further popularization and application. The utilization of biomass must take the path of efficient conversion and high-value utilization in order to realize its high value-added utilization. [0003] Biomass is the only renewable ca...

AI Technical Summary

Problems solved by technology

However, the application of related technologies still faces bottlenecks. For example, although the biochar produced by biomass pyrolysis and carbonization technology is a high-quality fuel or carbon material, it can also be used as soil improvement or carbon-based fertilizer, but its products are relatively single and its technical and economic efficiency is improved. limited, and the other main product, bio-oil, is currently difficult to use, and there are potential environmental risks; while the biomass gasification technology is still mainly based on air gasification, the calorific value of the gas produced is low and the tar content is high, which seriously limits its promotion application

[0004] In the process of biomass conversion and utilization, its physical and chemical characteristics and thermal conversion behavior characteristics should be fully considered. For example, crop straw biomass contains high ash content and alkali metal and alkaline earth metal content. When it is used as fuel, it often faces the problem of heating surface Dust accumulation, slagging, corrosion, and excessive emission of particulate matter; it is difficult to obtain single-phase bio-oil when used as raw material for rapid pyrolysis, which is not conducive to subsequent further upgrading; and because of its high volatile content, straw pyrolysis gas The tar content in chemical gas is relatively high, which poses a great challenge to its high-value utilization

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